4.1
Adit Mahmood
4/22/09
Block B Investigation 4: Multiplying and Dividing Integers
How do I multiply and divide integers?
A1. Suppose the temperature changed by an average of 3 degrees. Copy and complete the table below and use it to find the total temperature change over 5 hours.
Number of hours 1 2 3 4 5
Total temperature change +3 degrees +6 degrees +9 degrees +12 degrees +15 degrees
A2. Write a multiplication sentence that represents total change in temperature for the first five hours. Write a multiplicaton sentence that represents the change for the ten hours.
C1. Write the addition sentence from each number line below.
C2. Write the multiplication sentence from each number line below.
0+2+2+2=6
2*3=6
0+-3+-3=-6
-3*2=-6
0+-2+-2+-2+-2=-8
-2*4=-8
D. Make up a situtation for -4*10
In Springfield the temperature went down by an average of -4degrees per 1.2 months. What was the temperature after 10 months?
-40 degrees after 10 months.
E. Find each product E1. 5*-4=-20
E2. 20*-4=-80
E3. -4*20=-80
E4. -5*4=-20
F.U 1. Suppose the temperature changed by +2 per hour from it’s low of -4 degrees at 3:00 a.m. What will the time be at 1:00 p.m?
The temperature is 16 degrees. 2. Suppose the temperature changed by -1.5 degrees per hour from the high of +25 degrees at noon. What will the temperature be at 10:00 p.m? The temperature is -40 degrees. 3. When you add a positive and a negative number the result is positive or negative. But will it be the same for multiplication?
No it wouldn’t be the same if you multiply a positive and a negative. you would always get negative.
Adit Mahmood
4/22/09
Block B
Investigation 4: Multiplying and Dividing Integers
How do I multiply and divide integers?
A1. Suppose the temperature changed by an average of 3 degrees. Copy and complete the table below and use it to find the total temperature change over 5 hours.
Number of hours 1 2 3 4 5
Total temperature change +3 degrees +6 degrees +9 degrees +12 degrees +15 degrees
A2. Write a multiplication sentence that represents total change in temperature for the first five hours. Write a multiplicaton sentence that represents the change for the ten hours.
+3*1= +3 degrees
+3*2= +6 degrees
+3*3= +9 degrees
+3*4= +12 degrees
+3*5= +15 degrees
+3*6= +18 degrees
+3*7= +21 degrees
+3*8= +24 degrees
+3*9= +27 degrees
+3*10+ +30 degrees
B1. Suppose the temperature changed by -3 degrees. Copy and complete the table below for the first five hours.
Number of hours 1 2 3 4 5
Total Temperature change -3 degrees -6 degrees -9 degrees -12 degrees -15 degrees
B2. Write a multiplication sentence for the first five hours. Write a multiplication sentence for the entire 10 hours.
-3*1= -3 degrees
-3*2= -6 degrees
-3*3= -9 degrees
-3*4= -12 degrees
-3*5= -15 degrees
-3*6= -18 degrees
-3*7= -21 degrees
-3*8= -24 degrees
-3*9= -27 degrees
-3*10= -30 degrees
C1. Write the addition sentence from each number line below.
C2. Write the multiplication sentence from each number line below.
0+2+2+2=6
2*3=6
0+-3+-3=-6
-3*2=-6
0+-2+-2+-2+-2=-8
-2*4=-8
D. Make up a situtation for -4*10
In Springfield the temperature went down by an average of -4degrees per 1.2 months. What was the temperature after 10 months?
-40 degrees after 10 months.
E. Find each product
E1. 5*-4=-20
E2. 20*-4=-80
E3. -4*20=-80
E4. -5*4=-20
F.U
1. Suppose the temperature changed by +2 per hour from it’s low of
-4 degrees at 3:00 a.m. What will the time be at 1:00 p.m?
The temperature is 16 degrees.
2. Suppose the temperature changed by -1.5 degrees per hour from the high of +25 degrees at noon. What will the temperature be at 10:00 p.m?
The temperature is -40 degrees.
3. When you add a positive and a negative number the result is positive or negative. But will it be the same for multiplication?
No it wouldn’t be the same if you multiply a positive and a negative. you would always get negative.